Method of making tubular knives.



A. LATHAM.

METHOD 0F MAIUNG TUBULAR KNIVES. APPLICATION FILED MAY19, 191e.

v A i Patented Ap 1917. ZSHEETsl.

A. LATHAIVI.

METHOD 0F MAKING TUBULAR KNIVES;

APPLICATION FILED MAY I9 |916.

I Patented Apr. 3, 1917.

2 SHEETS-SHFET 2 mh' mwms harms hummm-umu,WAM/warum n c` 'UNITED @TATEE PATENT FFIQE.

ALBERT LATI-IAM, OF BEVERLY, MASSACHUSETTS, ASSIGNOR TO UNITED SHOE` MACHINERY COMPANY, OF PATERSON, NEW JERSEY, A CORPORATION OF NEW JERSEY.

METHOD OF MAKING TUBULAR KNIVES.

To all whom t may concern:

Be it known that I, ALBERT LA'iiiAM, a citizen of the United States, residing at Beverly, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Methods of Making Tubular Knives; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to a method of making tubular knives, and more particularly to a method of making knives employed for skiving leather and analogous material. Upper material is commonly skived prior to its introduction into a boot or shoe upon a machine of the general type shown and described in the United States patent to Alexander No. 1,079,462, dated November 25, 1913. In order that this machine shall operate at a maximum efficiency it is essential that all points of the cutting edge of the tubular knife shall be located in a true circle concentric with the axis of rotation of the knife.

It is the object of the present invention to produce a skiving knife by an improved method which may be practised at a minimum of expense, and which insures that the finished product shall have the desired qualifications.

With this object in view, a feature of the invention consists in forming a tubular shell, finishing a portion of the shell to a true cylindrical form, hardening the portion of the shell thus finished, finishing the unhardened portion of the shell to a true cylinder concentric with the hardened portion of the shell while the shell is held at the hardened portion, and finally grinding the vhardened portion while the shell is held at the unhardened finished portion.

In the accompanying drawings illustrating the improved method, Figure 1 represents the knife shell after having been drawn into approximately the desired shape and size with an inturned flange at one end; Fig. 2 illustrates the shell after the inner and outer surfaces and end face have been trued and reduced to approximately the desired size; Fig. 3 represents the shell after a portion has been hardened and the unhardened portions, including the inturned flange, have Patented Apr. 3, 1917.

Serial No. 98,615.

been finished; Fig. 4 represents the final operation upon the unhardened portion of the shell; and Fig. 5 represents the shell after the inner and outer surfaces of the hardened portion have been ground and the circular .cutting` edge has been formed.

In the present invention a substantially cylindrical tube is first cut to the proper length and is then operated upon in any suitable manner to form a tubular knife shell, as indicated at 1, having an inturned flange 2 at one end. In the illustrated einbodiment of the invention the knife shell is conveniently formed by drawing out a short length of tubing in one or more operations to form the shell, substantially as shown in Fig. 1 of the drawings.

After the knife shell has been suitably formed, the next step is to finish the inner and outer surfaces of the shell and the face opposite the inturned flange to approximately the desired dimensions. In performing this operation the shell is conveniently clamped by the inturned flange 2 to a clamping member having coperating clamping heads 3 and 4 which are moved relative to one another by a threaded adjusting member. l/Vhile held in position by the clamping members, the inner and outer surfaces of the shell are approximately finished, and the end of the shell opposite the inturned flange 2 is faced off, as indicated in Fig. 2 in which the dot and dash lines indicate the original dimensions of the shell and the full lines the final dimensions of the shell as finished. In addition, an annular recess 7 is formed in the inner surface of the shell in proximity to the inturned flange for a purpose to be hereinafter described. The operation of finishing the shell is conveniently accomplished by relatively rotating the cutting tool and shell so that at the completion of this operation a true cylindrical shell is formed of approximately the desired diameter and thickness and having the end which constitutes the cutting edge lying in a plane normal to the axis of the shell.

The shell thus formed is next hardened for a substantial portion of its length, which in the illustrated embodiment of the invention is that portion between the cutting face and vthe annular recess 7. It willi thus be seen that the annular recess forms a convenient inea-nsV for indicating the portion of the shell which is to be hardened; and as substantially all of the hardened portion is utilized for cutting purposes, the annular recess is sufficiently removed from the inturned flange to permit the proper clamping of the knife shell when the hardened portion has been completely ground away.

After the shell has been finished and hardened, as above described, the unhardened portions are nexttrued with the hardened portions and finished to the desired dimensions. To this end the hardened portion of the shell, which is substantially true, is clamped in a rotary chuck of suitable construction which locates the shell by the outer surface concentrically with the axis of rotation. This chuck may be of the general form indicated in Fig. 3 and having an annular ring 10 provided with a series of radially disposed locating pins 11 which are simultaneously actuated by a rotary ring 12 to center the shell in the chuck through engagement of the pins with the outer4 surface of the shell. After the shell has been centered it is clamped by a series of clamping members 13 engaging with the shell at thejunction of the inturned flange and the outer face of the shell, as shown clearly in the drawings. hile thus clamped in position, the unhardened and comparatively soft portions of the shell are finished to the desired shape and size, as indicated by the dot and dash lines in Fig. 3 of the drawings. At the completion of this operation a substantially true cylindrical shell is formed having an inturned flange whose opposite faces are normal kto the axis of rotation of the shell.

The shell is next clamped in a rotary head which corresponds with a head upon the skiving machine in which the knife is finally embodied. This head comprises a clamping member 15 having an annular recess 16 formed in the face and coperating with a clamping head 17 to clamp the shell by engagement with the inturnedflange, as shown clearly in Fig. t. As the flange has been previously faced olf and the inner edge trued, the shell is automatically centered and all points in the outer and inner surfaces of the shell lie approximately in the true circle of rotation of the shell. lVhile clamped in this manner the shell is-first operated onto round olf that portion of the shell forming the junction between the outer surface and the inturned flange and to complete the external finishing of the shell.

Finally the outer and inner surfaces of the shell are operatedV upon by suitable grindling members to accurately finish the shell and remove` any slight inequalities in the surface initially present or which may have developed in the hardening operation. In performing this grinding operation the shell is preferably engaged, as shown in Fig. 5, by an outer grinding disk 18 and an inner grinding disk 19, rotating about axes parallel to the axis of rotation of the shell. In the illustrated embodiment of the invention the cutting edge is simultaneously formed by a grinding disk 2() supported to rotate about an axis inclined to the axis of the shell and serving to bevel the outer face of the shell, as shown clearly in Fig. 5.

According to this method of manufacture the finished product is a true cylindrical shell having accurately formed surfaces and hardened throughout that portion of the shell which is to be utilized, for cutting purposes. In addition it will be obvious that, owing to the sequence of the various operations, the reduction of the shell to the proper dimensions is performed upon the unhardened portions of the shell and any slight distortion of the shell produced by the hardening operation is removed in the final grinding of the hardened portions of the shell.

Y The invention having been described, what is claimed is:

1. A method of making tubular knives', which consists in forming a tubular shell, finishing a portion of the shell to a true cylindrical form, hardening the portion of the shell thus finished, finishing the unhardened portion of the shell to a true cylinder concentric with the hardened portion of the shell while the shell is held at the hardened portion, and finally grinding the hardened portion while the shell is held at the unhardened finished portion.

2. A method of making tubular knives, which consists in forming a shell having an inturned fiange at one end, hardening a substantial portion of the shell extending from the edge opposite the flange, clamping the shell through engagement with the hardened portion and finishing the unhardened portions of the shell, and finally engaging the shell at the unhardened portion and grinding the hardened portions to nish the hardened portions of the shell and form a true cutting edge.

3. A method of making tubular knives, which consists in forming a substantially cylindrical shell, finishing the inner and outer surfaces of the shell to approximately the Vdesired dimensions, hardening a substantial portion of the shell thus finished, engaging the shell by the hardened portion Aand truing the unhardened portions of the shell to conform with the hardened portions, and finally engaging the shell at the unhardened finished portions and grinding the hardened portions.

t. A method of making tubular knives, which consists in forming a shell having an inturned flange at one end, engaging the shell at the fiange and operating upon the shell to form true cylindrical inner and outer surfaces, hardening the portion of the shell thus finished, centering the shell by a true cutting edge at one end of the har- 15 engagement With the outer hardened Surface and truing the unhardened portions to conform with the hardened surface.

5. A method of making tubular knives, which consists in forming a tubular knife shell, operating upon the shell to form true Cylindrical inner'and outer surfaces and to produce an annular recess in the inner surface7 hardening the portion of the shell thus finished, forming true cylindrical surfaces upon the unhardened portions of the shell While the shell is held by engagement With the hardened portions, and inally forming dencd portion of the shell While the shell is held by the unhardened portion.

6. A method of making tubular knives, Which consists in forming a tubular shell, hardening a portion 91": the shell, iinishing the unhardened portion of the shell While held at the hardened portion, and finally clamping the shell at the unhardened portion and simultaneously grinding the inner and outer surfaces of the shell to form an outer Cylindrical shell provided With a loeveled cutting face upon the outer surface.

` ALBERT LATHAM.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

